One of the goals of this project is to gain a better understanding of the mechanisms which control the magnitude and pattern of distribution of dividing cells in the ocular lens. It is felt that the results obtained may have significance in the field of ophthalmology as well as other fields of the bio-medical sciences in which the mechanism(s) which controls cell division and growth play an important role. Our current studies indicate that it is possible to stimulate cell division in the cultured lens using a completely defined medium. The specific aims of this project are to identify the components of the culture medium that are responsible for the stimulation of DNA synthesis, mitosis and cellular migration, which is observed in lenses cultured in the presence of either rabbit serum or insulin. We also propose to further identify the serum factor(s) which triggers mitosis and cell migration and to probe the mechanism and site of action by which the serum factor(s) and insulin induce mitosis. The results obtained in vitro will be compared to biochemical and morphological changes that precede and accompany injury- induced mitosis and migration in vivo. In both in vivo and in vitro studies attention will be focused upon any changes, (e.g. changes in macromolecular synthesis, i.e., RNA, DNA and protein synthesis and morphological changes at the electron microscope level) which may characterize the newly-stimulated cells. The long-term goal of this study is the elucidation of the biological mechanism(s) that control cell division and migration in the ocular lens.